Suppose that for whatever reason the trap in question is never disabled, perhaps because there is no rogue or perhaps because no one can find its moving parts due to unlucky Perception rolls. The trap might be a corridor that shoots fire or lightning every couple of rounds, clockwork pendulums that keep swinging forever, or anything else that won't exhaust itself after a set number of rounds. Is the trap defeated and XP rewarded when the party successfully gets past it into the next room? What if they revisit the trap room multiple times? Does it matter if the trap inflicts damage on the first visit or on subsequent visits? If combat occurs in the trap room during a subsequent visit, how does its presence affect the challenge rating?

\$\begingroup\$Could you clarify what kind of trap it is? It seems like the crux of the question is similar to the question of whether or not to give the Players any XP for finding non-combat ways to get around something. Either way, I'll also leave this here: webpages.charter.net/tedsarah/Pathfinder/utilities/…\$\endgroup\$
– smiley trashbagOct 6 '17 at 19:54

4 Answers
4

Overcoming the challenge of a trap involves encountering the trap, either by disarming it, avoiding it, or simply surviving the damage it deals. A trap never discovered or never bypassed was not encountered (and hence provides no XP award).

Simply surviving the damage it deals establishes a pretty low bar.

Since Pathfinder is an OGL expansion of 3.5, these extra details not in the SRD did not get ported, but it would probably be reasonable to assume the same without further explanation from the Pathfinder rules.

Is the trap defeated and XP rewarded when the party successfully gets past it into the next room? What if they revisit the trap room multiple times? Does it matter if the trap inflicts damage on the first visit or on subsequent visits? If combat occurs in the trap room during a subsequent visit, how does its presence affect the challenge rating?

Ultimately, this will be up to the DM, however, I would recommend, as a guideline, consider rewarding XP if there's risk to the party and effort in avoiding or mitigating that risk each time they encounter the trap.

Keep a list of the CRs of all the monsters, traps, obstacles, and
roleplaying encounters the PCs overcome. At the end of each
session, award XP to each PC that participated. Each monster, trap,
and obstacle awards a set amount of XP, as determined by its CR,
regardless of the level of the party in relation to the challenge,
although you should never bother awarding XP for challenges that have
a CR of 10 or more lower than the APL. Pure roleplaying encounters
generally have a CR equal to the average level of the party (although
particularly easy or difficult roleplaying encounters might be one
higher or lower).

A trap is generally meant to block access to somewhere or something. You overcome the trap by gaining access to the thing or place the trap is protecting.

Look at all the ways an encounter can be overcome. How can you gain access?

Spring the trap (for a non resetting trap)

disable the trap

Learn how to bypass the trap (e.g.: only step of the white squares)

Go around the trap (find another door, smash the chest, etc.)

Take the thing the trap protects

Exit the area the prison the trap is keeping you in

They use some kind of skill or magic to determine that there is
nothing useful behind the trap.

The only times that I wouldn't reward experience is times when the players just don't play (they give up getting on the item, going to a mission critical area, or don't know/find out if there is anything useful there).

As soon as the PC's have interacted and the encounter is finished

A trap is a type of encounter that the players can face, but not the only one. Many types of encounters will require some GM discretion as to when the challenge was defeated, like monsters being killed, traps disabled, haunts exorcised, and so on.

But is the XP awarded when monsters are killed and only that, or they gain XP if they are charmed/dominated, or scared away as well? What if the party runs away from the monsters? Ultimately, that is a GM decision, but he shouldn't penalize players that defeat the encounter on clever ways, and sometimes, running away is the best (or only) option against an encounter.

Most encounters present combat with monsters or hostile NPCs, but there are many other types—a trapped corridor, a political interaction with a suspicious king, a dangerous passage over a rickety rope bridge, an awkward argument with a friendly NPC who suspects a PC has betrayed him, or anything that adds drama to the game.

What all these things have in common? The player characters had to interact with the world somehow. There was some drama behind this interaction, there was danger, or tension, or even something to be gained or lost from it depending on the actions that the players decided to take.

For every obstacle that the players are presented with, there is (or should be) a defined Challenge Rating as part of the designed encounter.

Challenge Rating (or CR) is a convenient number used to indicate the relative danger presented by a monster, trap, hazard, or other encounter—the higher the CR, the more dangerous the encounter.

Encounter: An encounter is a short scene in which the
PCs are actively doing something. Examples of encounters
include a combat with a monster, a social interaction
significant to the adventure’s plot, an attempt to disarm
a trap, or the discovery of a mystery or clue requiring
further investigation.

This also confirms that an encounter happens as soon as there is some kind of interaction with the dangers presented. Here, even attempting to disarm the trap counts as an encounter already. They don't have to fall into the spiked pit, but they can't simply go into another direction in the dungeon and ignore it altogether. They have to interact with the trap in away or another. Either by finding it, attempting to disarm it, trigger it on purpose to figure out the effect, or to overcome it in clever ways.

Sound: This trigger springs a magic trap when it detects any sound. A sound trigger functions like an ear and has a +15 bonus on Perception checks. A successful Stealth check, magical silence, and other effects that would negate hearing defeat it.

Another example of this, certain traps on Reign of Winter simply have to be found (and avoided, obviously, unless you want to trigger it) to award XP:

Regardless of how many mines are triggered or found, award XP only once per minefield (a total of two CR 11 encounters), when a mine either goes off or is found or disabled.

Similarly, if you defeat a monster or NPC that you have defeated before, that enemy should not award experience again. Unless he is part of another encounter altogether. In that case, there must be something different from last time, like new monsters accompanying him, the trap's location changed and it has to be found again, there is something else making the trap harder than before, like a monster suddenly blocking the door in a room with swinging scythes.

You simply have to ask yourself the following questions:

"Is this a new encounter?"

"Does this add drama to this encounter?"

If the answer is Yes to both questions, award XP once more. Your players deserve it.

When to award this experience is something else that is also GM fiat. Some GM's prefer to award it right away, others will note that the encounter is defeated and award at the end of the session, others will take some time calculating the experience points between sessions and award at the start of the next session. There are GM's that will not even track experience, and level up the characters as soon as he finds that is appropriate. Paizo even supports this on the published adventures with certain milestones noted for each part of the adventure.

Characters advance in level by defeating monsters, overcoming challenges, and completing adventures—in so doing, they earn experience points (XP for short). Although you can award experience points as soon as a challenge is overcome, this can quickly disrupt the flow of game play. It’s easier to simply award experience points at the end of a game session—that way, if a character earns enough XP to gain a level, he won’t disrupt the game while he levels up his character. He can instead take the time between game sessions to do that.

Keep a list of the CRs of all the monsters, traps, obstacles, and roleplaying encounters the PCs overcome. At the end of each session, award XP to each PC that participated. Each monster, trap, and obstacle awards a set amount of XP, as determined by its CR, regardless of the level of the party in relation to the challenge, although you should never bother awarding XP for challenges that have a CR of 10 or more lower than the APL. Pure roleplaying encounters generally have a CR equal to the average level of the party (although particularly easy or difficult roleplaying encounters might be one higher or lower).

There are few exceptions to this, like a Phoenix that could possibly have to be killed twice in the same encounter to be counted as defeated.

What does James Jacobs say?

XP for traps is based on the trap's CR, just like a monster. It's less clear when the XP should be awarded. I can always just do what feels right, of course, but I'd really like a specific citation of the RAW.

I'm really not sure how listing a trap's XP in its stat block (which is what we do for EVERY trap in EVERY adventure we publish) isn't obvious enough, to be honest.

ALL XP awards in the game are handed out when the thing they're attached to is defeated. Be that a monster or a trap or a haunt or a tense political standoff. Be "defeated" akin to "killed" or "driven away" or "disabled" or "endured.

AKA: You get full XP for a trap if you detect it/disable it, if you trigger it and survive its effects, or if you detect it and avoid it. You don't get the XP more than once (so if you detect and avoid it then come back later and disable it or endure its effects, you don't get to double dip).

This not only supports the idea but also supports what they have written in the Gamemastery Guide and published adventures.

I don't know what is the official way to handle this. Personally I use this:

If the trap is a fake door, fake chest, or anything that the PCs have no reason to interact with once they figured it is a trap, then the trap is considered "defeated" when figured out.

If the trap is linked to a passage I consider it defeated when the PCs cross it for the first time. If they come back later in the passage they still can have trouble with it, but won't get the XP again.